Summary

Could a bacterial pathogen that inhabits the human stomach reveal the paths trodden by our ancestors as they migrated out of Africa? In his Perspective,
Spratt
discusses an analysis of isolates of the gastric pathogen
Helicobacter pylori
from 27 human populations of different ethnicities and from different geographical locations (
Falush
et al.). DNA sequence differences among the bacterial isolates revealed traces of ancient human migrations and of the intermixing that occurred as migrating populations colonized new areas.